Thoroughly enjoyable "scripted documentary". All sailors are actual RN Seamen and they do a very good job of portraying themselves - no over the top acting - just simple lines realistically delivered. One fascinating thing, the number of lung cancer and heart disease victims in the 1960's-70's must have been staggering. EVERYONE, Captain to swabbies, smokes constantly - even on duty(!) and buying, giving, using, sharing, talking about tobacco is a constant theme. Well worth watching even if it is a bit slow at times, but that is the reality of submarine duty -long and boring then fast and furious.